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DIY Control Loader Software

BFF Control Loader (Force Feedback) Software


BFF Control Loader SoftwareThe BFF Control Loader software runs with FS9/X and X-Plane flight simulators to generate force demands for DIY FFB flight controls. It provides outputs compatible with the CL_SPU + BLDRV2-24 brushless motor drivers available on the site.


BFF Control Loader Quick Start Guide - Online  


BFF Control Loader Software Download


To unlock the software on a specified PC you must run the software then follow the registration prompts and email your PC ID to me. I can then send you the unlock key for that PC.


The software will run unregistered in DEMO mode - the force output will release after 10 minutes of running time. A non-commercial home-use licence is included with the price of CL_SPU + BLDRV2-24 card orders. For commercial use registration of the software please contact me.


BFF CL Configuration Manager

New Configuration Manager



Version V1.3 includes a new Configuration Manager which brings all the system settings under a single set up application.


Once installed please use the IMPORT button in the Configuration Manager to import your existing CL system settings.


More details in the On-Line User Guide.





Version V1.122 of the CL software adds portable USB Dongle licensing.


The USB dongle allows a software registration to operate on any PC the dongle is plugged into. With the normal non-portable registration your unlock key works only on your specified PC.


For more details click on the Dongle image on the right.




See also...



CL_SPU + BLDRV2-24 Brushless Driver for Control Loader Systems

For FS9/X you will need an up-to-date version of Pete Dowson's FSUIPC installed. And for use with X-Plane 9.6+ & v10 you will need to install Torsten Spiering's XPUIPC v1.9.0 or later. For both see links to the right......


(Many thanks to Torsten Spiering for the use of XPUIPC.)


BFF CL Software features

The CL system was developed principally for leisure simulators with GA aircraft behaviours. The flight control forces simulated by the BFF CL Software include:

  • Airspeed dependent aerodynamic loading (returning forces proportional to control surface displacement and airspeed)

  • Adjustable aerodynamic force gains (equivalent to adjustable control surface area)

  • Angle of attack (alpha and beta) effects (eg for longitudinal stability response)

  • Realistic GA trim behaviour (independent of simulator trim system, controls can be trimmed in any position) using trim potentiometers or trim buttons/switches.

  • Control surface static & dynamic weight effects (aircraft acceleration effects)

  • Prop-wash effects

  • Engine vibrations (vary with power & rpm)

  • Runway vibration effects (vary with runway speed)

  • Stall buffeting effects (frequency and amplitude definable - eg stick vibration type behaviour)

  • Damping and friction adjustments (-ve gains definable)

  • Auto Pilot following (native sim AP only - when used with CL_SPU + BLDRV2-24 drivers)

  • Separate configuration program with saveable configuration settings

  • NEW for V1.120 - helicopter cyclic trim loading mode.

  • NEW for V1.210 - Heavy Jet mode.

  • NEW for V1.3 - Configuration Manager, support for Sim-Avionics & ProSim, and also Failure Mode Loading.


BFF CL Configuration ManagerWhen used with the CL_SPU + BLDRV2-24 brushless motor drivers the CL software exports flight simulator dependent force components at approximately 75Hz. These are added to the force components calculated onboard the BLDRV2-24 card at 500Hz. The on-board force processing of the BLDRV2-24 allows the CL software to run with minimal system resource which allows it to run on the same PC as the flight sim.


The included Configuration Manager application allows the configuration settings to be adjusted and saved in configuration files and to be updated in the main CL software as it runs. This allows the force effects to be tuned with the FFB active.


Control Loading Model


The loading calculation model has been developed to provide effective force demands for low cost DIY systems (compared to commercial control loader systems) and is principally based on the behaviour of GA aircraft with reversible controls. The model uses control axis position and velocity as the indicator of control surface position and velocity, this is measured at the brushless motor quadrature encoder. Airspeed, aircraft AoA, accelerations, engine condition, runway speed, stall state and other dynamic flight data are all taken live from the flight sim (FS9/X or X-Plane). Trim surface position is taken from the independent trim pot positions or trim button/switch operation.


Aerodynamic loads are calculated from control surface deflection and aircraft AoA and airspeed. The airspeed exponent used in the calculation of control surface lift can be adjusted to suit different control types. For small aircraft with controls mechanically connected to the control surfaces airspeed squared can be set. For fly-by-wire systems a linear relationship can be set (stiffness varies linearly with airspeed).


The model allows control forces to be calculated without the need to monitor applied loading and this greatly reduces the complexity and cost for DIY systems by avoiding the need for force sensors in the controls.


For Auto Pilot following the CL_SPU + BLDRV2-24 cards switch automatically into a PID controlled position following mode and the CL software generates position demands based on the AP control actions read from the flight sim. The AP following can be disengaged by moving the controls or by the usual sim instruments.


AP following can be disabled if not required. Note that the AP following functionality is active for the simulator software's native AP system only - not for external AP packages. UPDATE - AP following for Sim-A and Pro Sim are now also available in the recent software versions.





To operate effectively the software must be used in a properly designed and built system as described on the BLDRV2-24 page. The quality of the force feedback you obtain will be critically dependent on the quality of the design and build of the force transmission and other mechanical elements in your controls.



The previous CL Software web page and versions is here.




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